The Importance of Hoses in Chemical Plants

To understand the significance of hoses in chemical plants, one must have a thorough understanding of the chemical industry and its processes. Mrinal Das, a Chemical Engineer from LIT Nagpur with a Masters in Business Administration from ICFAI, has over thirty years of experience in the field. Hose + Coupling World was pleased to speak with Das to learn more about the importance of hoses in this dynamic industry.

By Contributing Editor

Mrinal Das.

Procurement Process

During the procurement process at Dorf Ketal, the vendor list for all of the components in a project is developed. This includes pipes, fittings, hoses, couplings, equipment, instrumentation, and electrical elements. “We float the inquiries with the proper specifications and either contract an engineer, a consultant, or from time-to-time, we do it ourselves,” said Das. Sometimes, for special purchasing activities, the company works with other companies on a nomination basis. Before a company can be put on the vendor list, Das completes due diligence of the supplier to verify their credibility and the quality of their products. Once the list is specified, orders are placed, inspections are conducted, and finally, the components are delivered and installed. The list of vendors is reviewed on an annual basis, and if a supplier’s performance is not up to par, a new vendor is added in its place.

Types of Hoses and Testing

Das works with several different types of couplings and hoses. While the company uses many types of hoses to transfer chemicals, Das explained that there are specific hoses that work best and are widely used in chemical plants. “We typically use PP composite hoses, stainless steel corrugated hoses, pyro protect pen flexible firefighting hoses, rubber hoses for steam applications, and nylon braided PVC hoses. The PP composite hoses we use are mostly made of stainless steel 304, stop end, and swivel flanges that are about 150 pounds and conform to the EM 13765. For corrugated hoses, we add on a PVC shielded part, which is usually an NPT-type connector in SS 316 with both ends conforming to the 6501 BS standards,” explained Das.

They also use hoses that are compatible with camlock and swivel fittings.

The hoses are tested before delivery to ensure they are operational. A hydro or pneumatic test is typically performed onsite to make sure there are no leakages. Das said it is important to test the hoses once a month for routine maintenance. In case of failure, the original supplier will replace the hose; however, the company also keeps spares on hand for critical applications. As safety is of the upmost importance in a chemical plant, rigorous testing is conducted.

Hose Storage Issues

Many obstacles present themselves when hoses are stored improperly and fail as a result. Storing hoses can be a difficult process because they need to be folded. This means there is always a chance that the braiding will be damaged. Storing couplings is also challenging because they are prone to leakages if they are not tightened or handled properly. A common problem that Das has faced when hoses or couplings rub against other surfaces is aberrations. Additionally, erosion of the internal tubing, incorrect assembly, fitting failures, and high temperatures, especially with steam, are other issues he has encountered. “I have seen premature hose failures occur because of leakages and weeps in the coupling.

This can cause the coupling to blow off, corrode, crack, blister, swell, or flare,” said Das. It is important to bundle, and clamp hoses properly, and protect them with proper covers. One of the most prevalent challenges with protecting hoses, especially in India, is a lack of jacketed hoses. Without the jacket, hose are much more susceptible to their environment and tend to degrade at an accelerated pace.

Although discouraged due to safety concerns, operators will occasionally attempt to modify hoses on their own. It is strongly advised that the appropriate steps be taken when considering a hose for a sever service application, as the use of a hose that fails to comply with the application requirements could result in serious injury to the operator.

The Importance of Quality Hose Materials

Firefighting hoses that are double braided and come from canvas sources have always had a large market in chemical plants. When firefighting hoses are folded and not used for a long time, they are prone to cracking and need to be replaced. Therefore, some companies have turned to hoses made from materials of higher quality. In India, many firefighting facilities use copper alloy or bronze couplings instead, which are more expensive.

It is important to use sophisticated, high-quality hoses because if anything goes wrong, it may result in property damage or injury. As hoses are being used in almost every industry, it is important to consider what kind of hoses to use for each specific application. For instance, compressed air hoses, water hoses, and hot water hoses are used for ducting, firefighting, automotive, food, trucks, and dredging in railways. “Although they may seem insignificant, hoses are an integral part in any chemical plant similar to valves and piping, which people are thankfully beginning to understand,” expressed Das.

Advancements and New Hose Technologies

“In recent years, hoses have been overlooked as extremely important parts of chemical plants; now that their importance is becoming clearer, people are starting to implement better materials and reinforcements in the construction process,” said Das. Industry professionals are also going to exhibitions and seminars, and trying to learn more about the various types of hoses. Fittings are likewise improving, as they are subject to more rigorous quality checks and more stringent specifications, especially with high pressure, chemical and multipurpose hoses. There have been significant advancements in the manufacturing process. “One of the reasons that stainless steel is so commonly used as a material is because it is corrosion-resistant and it allows for cleanliness of the final product,” he said. Otherwise, chemicals can cause rusting and impurities in hoses and couplings.

Final Thoughts

Due to demanding environments and processes, hoses play a fundamental role in chemical plants. Extreme temperatures, the mixing and transfer of hazardous compounds, and equipment configurations lead to subpar piping situations and often require a specialized hose to transfer the media. Das highlights his personal experience in using hoses for loading and unloading liquid ammonia at -33˚C, concluding that he has seen how critical they are firsthand.


Mrinal Das started his career in the petrochemical refinery industry and has now shifted his focus towards a specialty in the chemical industry. He has done Project Management in the USA and was Steering Committee Member in Stainless Steel World International, Flow Control Exchange, and actively involved in Valve World and Heat Exchanger World. He currently works as Senior Vice President at Dorf Ketal, a global chemical manufacturing and supply company, where his responsibility is to conceptualize, estimate and execute projects while acting as the head of procurement and purchasing in Mumbai, India.

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